Preschool is usually the place where a lot of children can be assessed if they are all ready to go to school. At the same time, it can prepare them for kindergarten which can be hard for some kids. Usually, the children who are in preschool are 2 years old to 5 years old.
There are also some rules that they need to follow. For example, those who are in preschool should already be potty trained. Those who are in daycare are children who are cared for by professional carers. The children are usually left there while their parents go to work or do some errands.